It sounds like an interpolation issue to me, i.e. on your Solaris machine you are actually running the match against ( *[Cc] *), not \( *[Cc] *\). Are you actually running the same script file on the two machines? Can you show us your assignment statement (copy/paste) for @WORD_LIST? Neither the regex syntax nor the String interpolation syntax should vary between the two versions of perl.
Bingo. It was a problem with the word list file. When I did a more thorough examination, I didn't have the "\" in the search term. Adding them made the search work correctly. It was a very vexing problem, as I could see no reason that it should parse differently.
Thank you for the assistance.
Status: Resolved.